Preparation of Optically Active Apoverbenone and Verbenone from Nopinone by Use of the Sulfenylation−Dehydrosulfenylation Method. Stability and Reactivity Attributable to Absolute Configuration at the Sulfur Atom in Sulfoxides
作者:Hiroshi Kosugi、Jaseung Ku、Michiharu Kato
DOI:10.1021/jo9807316
日期:1998.10.1
with 19a. As a result, it was proved that, in 3-(phenylsulfinyl)nopinones, thermodynamic stability of isomers is dependent on absolute configuration at the sulfur center; that is, the trans-isomer 10a possesses an R(s)-phenylsulfinyl group and the cis-isomer 10b possesses an S(s)-phenylsulfinyl group, and it was proved that, in (4R)-4-methyl-3-(phenylsulfinyl)nopinones, both cis-isomers 18a,b are stable
旋光形式的Apoverbenone(4)和verbenone(5)作为对映选择性合成中的手性来源,可能是有用的化合物。以易于从(-)-β-pine烯,(+)-apoverbenone(4a)和(+)-verbenone(5a)购得的(+)-nopinone(1)开始,以合成上令人满意的总收率制备,通常使用亚磺酰化-脱氢亚磺酰化方法涉及烯酮官能团的构建。该方法学可适用于从(-)-去甲酮开始制备其对映体(-)-4b和(-)-5b。虽然亚砜10a,b和18a,b中的苯亚磺酰基的构型是通过(1)H NMR光谱和NOE相关性确定的,但通过在(1)H NMR光谱中比较它们的同系物,可以得出硫原子的绝对构型绝对配置明确的 即10a与13a,10b与13b,18a与19b和18b与19a。结果证明,在3-(苯基亚磺酰基)nopinones中,异构体的热力学稳定性取决于硫中心的绝对构型;即,反式异构体10a